Virtualization is being rapidly adopted across the information technology industry. Virtualization generally allows any number of virtual machines to run on a single physical machine, with each virtual machine sharing the resources of that one physical machine. Different virtual machines can run different operating systems and multiple applications on the same physical computer. Virtualization may be implemented by inserting a layer of software directly on the computer hardware in order to provide a virtual machine monitor or “hypervisor” that allocates hardware resources of the physical computer dynamically and transparently. The hypervisor affords an ability for multiple operating systems to run concurrently on a single physical computer and share hardware resources with each other.
Commercially available virtualization software such as VMware® vSphere™ may be used to build complex virtual infrastructure, including private and public cloud computing and storage systems, distributed across hundreds of interconnected physical computers and storage devices. Such arrangements advantageously avoid the need to assign servers, storage devices or network bandwidth permanently to each application. Instead, the available hardware resources are dynamically allocated when and where they are needed. High priority applications can therefore be allocated the necessary resources without the expense of dedicated hardware used only at peak times.
As virtual infrastructure becomes more complex and more widely distributed over larger numbers of physical machines, coordinating the operation of multiple architectural components becomes increasingly important. For example, multiple architectural components such as throughput schedulers and resource managers may be provided by different vendors and yet all may require interaction with the same underlying hardware. This can present a significant problem in that there is generally no formal coordination among such components in conventional implementations.